Motorola MPC533 Reference Manual page 689

MPC53x CAN System
Each CAN station is connected physically to the CAN bus through an external transceiver.
The transceiver provides the transmit drive, waveshaping, and receive/compare functions
required for communicating on the CAN bus. It can also provide protection against damage
to the TouCAN caused by a defective CAN bus or a defective CAN station.
16.2.1 TouCAN Signal Sharing
The CNTX0 and CNRX0 signals of TouCAN B are available at all times. The signal
functions for these signals is controlled by the TCNC bits in the PDMCR2 register.
Only one function can be enabled on a signal at a time.
16.3 TouCAN Architecture
The TouCAN module uses a flexible design that allows each of its 16 message buffers to
be designated either a transmit (Tx) buffer or a receive (Rx) buffer. In addition, to reduce
the CPU overhead required for message handling, each message buffer is assigned an
interrupt flag bit to indicate that the transmission or reception completed successfully.
16.3.1 Tx/Rx Message Buffer Structure
Figure 16-3 displays the extended (29-bit) ID message buffer structure.
MOTOROLA
PRELIMINARY—SUBJECT TO CHANGE WITHOUT NOTICE
CAN Station 1
CAN
Controller
(TouCAN)
CNTX0 CNRXO
Transceiver
Figure 16-2. Typical CAN Network
Chapter 16. CAN 2.0B Controller Module
CAN Station 2
ºº
Transceiver
NOTE
TouCAN Architecture
CAN Station n
Transceiver
16-3